The device is not under a service contract; the hospital did not involve dräger in examination and repair of the device.It was only reported that the ventilator motor had failed.Under these circumstances is neither a case-specific investigation possible nor a reliable conclusion about the exact nature of the error condition.However, in reflection of the device age of 13.5 years it is seen likely that wear-and-tear related abrasion of the collector disc had resulted in development of positions where the motor does not provide mechanic power due to contact interrupts to the carbon brushes; speed fluctuations will be the consequence.Since the motor speed is being monitored continuously, the speed fluctuations result in a deviation between measured and expected piston position.To prevent from potentially hazardous output and/or from damages to the ventilator unit the system is designed to shut down automatic ventilation and to alert the user to this condition by means of a corresponding alarm.Manual ventilation and the monitoring functions remain available to the full extent.Dräger finally concludes that the device behaved as specified upon the malfunction of a single component after more than 13 years of use; no patient consequences have been reported.Given that the postulation about the error condition is true the repair exchange will fully solve the device problem.The number of similar cases, related to the same root cause, is within the expected range of the respective risk assessment and thus accepted.
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